Membrane unit element, semipermeable membrane, filtration device, and processes for manufacturing the same

Abstract

The object of the invention is a unit element forming a membrane comprising a semi-permeable material able to separate in two compartments a filtration device for extracorporeal treatment of a fluid such as blood or plasma, said material being negatively charged, said element having a first internal face intended to be in direct contact with blood or plasma and a second external face intended to be in contact with filtrate, wherein said second face of said element is treated on the surface by one selected in the group comprising at least a cationic polymer, a mixture of polymers of which at least one polymer is cationic. The unit element can also have said first face treated on the surface by one selected in the group comprising: at least one cationic polymer, a mixture of polymers of which at least one polymer is cationic. The object of the invention is also a semipermeable membrane consisting of such unit elements; a filtration device for extracorporeal treatment of a fluid such as blood or plasma comprising two compartments separated by such a semipermeable membrane. The object of the invention is also the processes for manufacturing such devices.

1 . A unit element forming a membrane comprising a semi-permeable material able to separate in two compartments a filtration device for extracorporeal treatment of a fluid such as blood or plasma, said material being negatively charged, said element having a first internal face intended to be in direct contact with blood or plasma and a second external face intended to be in contact with filtrate, wherein said second face of said element is treated on the surface by one selected in the group comprising: 
 at least a cationic polymer,    a mixture of polymers of which at least one polymer is cationic.    
     
     
         2 . Unit element according to  claim 1 , wherein said first face is treated on the surface by one selected in the group comprising: 
 at least one cationic polymer,    a mixture of polymers of which at least one polymer is cationic.    
     
     
         3 . Unit element according to  claim 1 , wherein said material of the membrane is a copolymer of acrylonitrile and at least one anionic comonomer.  
     
     
         4 . Unit element according to  claim 1 , wherein said material of the membrane is a copolymer of acrylonitrile and at least one ionizable comonomer.  
     
     
         5 . Unit element according to  claim 3  or  4  wherein the comonomer comprises units derived from at least another olefinic unsaturated monomer capable of being copolymerized with acrylonitrile.  
     
     
         6 . Unit element according to  claim 3  or  4 , wherein said comonomer is olefinically unsaturated and carrying anionic groups selected from sulfonates, carboxyls, phosphates, phosphonates and sulfates.  
     
     
         7 . Unit element according to  claim 6 , wherein the said material of the membrane is a copolymer of acrylonitrile and sodium methallyl sulfonate.  
     
     
         8 . Unit element according to  claim 1 , wherein said at least one cationic polymer is a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.  
     
     
         9 . Unit element according to  claim 8 , wherein said polyamine is a polyethyleneimine.  
     
     
         10 . Unit element according to  claim 1  or  2 , wherein it is a hollow fiber.  
     
     
         11 . Unit element according to  claim 1  or  2 , wherein it is a sheet film.  
     
     
         12 . Process for manufacturing a hollow fiber unit element according to  claim 1  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one anionic comonomer,    (ii) extruding the resulting product through a die having two concentric nozzles, a fluid being injected in the internal nozzle to form the lumen of the hollow fiber and then thermomechanically treating the gel fiber leaving the die and    (iii) treating the external face of said hollow fiber by dipping or spraying a solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         13 . Process for manufacturing a hollow fiber unit element according to  claim 1  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one ionizable comonomer,    (ii) extruding the resulting product through a die having two concentric nozzles, a fluid being injected in the internal nozzle to form the lumen of the hollow fiber and then thermomechanically treating the gel fiber leaving the die and    (iii) treating the external face of said hollow fiber by dipping or spraying a solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyidextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         14 . Process according to  claim 12  or  13  wherein said comonomer comprises units derived from at least another olefinic unsaturated monomer capable of being copolymerized with acrylonitrile.  
     
     
         15 . Process for manufacturing a hollow fiber unit element according to  claim 2 , comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one anionic comonomer,    (ii) extruding the resulting product through a die having two concentric nozzles, a fluid being injected in the internal nozzle to form the aperture of the hollow fiber and then thermomechanically treating and stretching the gel fiber leaving the die;    (iii) treating the external face of said resulting hollow fiber by dipping or spraying a solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups and    (iv) treating the external face of said hollow fiber with said solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         16 . Process for manufacturing a hollow fiber unit element according to  claim 2 , comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one ionizable comonomer,    (ii) extruding the resulting product through a die having two concentric nozzles, a fluid being injected in the internal nozzle to form the aperture of the hollow fiber and then thermomechanically treating and stretching the gel fiber leaving the die;    (iii) treating the external face of said resulting hollow fiber by dipping or spraying a solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups and    (iv) treating the external face of said hollow fiber with said solution containing at least one cationic polymer being at least one hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         17 . Process according to  claim 15  or  16  wherein said comonomer comprises units derived from at least another olefinic unsaturated monomer capable of being copolymerized with acrylonitrile.  
     
     
         18 . Process for manufacturing a sheet film unit element according to  claim 1  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one anionic comonomer;    (ii) extruding after filtration and degassing of said polymer solution through a die having the form of a slot on a rotating cylinder; and    (iii) treating the external face of said sheet film by atomizing a solution containing at least one cationic polymer being a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         19 . Process for manufacturing a sheet film unit element according to  claim 1  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one ionizable comonomer;    (ii) extruding after filtration and degassing of said polymer solution through a die having the form of a slot on a rotating cylinder; and    (iii) treating the external face of said sheet film by atomizing a solution containing at least one cationic polymer being a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         20 . Process according to  claim 18  or  19  wherein said comonomer comprises units derived from at least another olefinic unsaturated monomer capable of being copolymerized with acrylonitrile.  
     
     
         21 . Process for manufacturing a sheet film unit element according to  claim 2  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one anionic comonomer;    (ii) extruding after filtration and degassing of said polymer solution through a die having the form of a slot on a rotating cylinder; and    (iii) treating the external face of the resulting sheet film by atomizing or dipping a solution containing at least one cationic polymer being a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyidextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         22 . Process for manufacturing a sheet film unit element according to  claim 2  comprising the steps of: 
 (i) preparing a polymer solution containing a copolymer of acrylonitrile and at least one ionizable comonomer;    (ii) extruding after filtration and degassing of said polymer solution through a die having the form of a slot on a rotating cylinder; and    (iii) treating the external face of the resulting sheet film by atomizing or dipping a solution containing at least one cationic polymer being a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.    
     
     
         23 . Process according to  claim 21  or  22  wherein said comonomer comprises units derived from at least another olefinic unsaturated monomer capable of being copolymerized with acrylonitrile.  
     
     
         24 .  24 . Semipermeable membrane consisting of a bundle of hollow fiber unit elements according to  claim 1 .  
     
     
         25 . Semipermeable membrane according to  claim 24  wherein the first internal face of said unit element is treated on the surface by at least one cationic polymer or a mixture of polymers of which at least one polymer is cationic.  
     
     
         26 . Semipermeable membrane consisting of sheet film unit elements according to  claim 1 .  
     
     
         27 . Semipermeable membrane according to  claim 26  wherein the first internal face of said unit element is treated on the surface by at least one cationic polymer or a mixture of polymers of which at least one polymer is cationic.  
     
     
         28 . Filtration device for extracorporeal treatment of a fluid such as blood or plasma comprising two compartments separated by a semipermeable membrane mounted in a casing, a first internal compartment being intended for blood or plasma circulation and fitted with two accesses and a second external compartment being intended for filtrate circulation and comprising one or two accesses, both compartments being in addition separated by a potting compound, based on an appropriate adhesive compound, forming a cylindrical partition for separating the two compartments of said device comprising a semipermeable membrane consisting of a bundle of hollow fiber unit elements according to  claim 1 .  
     
     
         29 . Filtration device for extracorporeal treatment of a fluid such as blood or plasma comprising two compartments separated by a semipermeable membrane mounted in a casing, a first internal compartment being intended for blood or plasma circulation and fitted with two accesses and a second external compartment being intended for filtrate circulation and comprising one or two accesses, both compartments being in addition separated by a potting compound, based on an appropriate adhesive compound, forming a tight seal in said device comprising a semipermeable membrane consisting of sheet film unit elements according to  claim 1 .  
     
     
         30 . Process for manufacturing a filtration device for extracorporeal treatment of a fluid such as blood or plasma comprising two compartments separated by a semipermeable membrane mounted in a casing, a first internal compartment for blood or plasma circulation and fitted with two accesses and a second external compartment for filtrate circulation and fitted with one or two accesses, both compartments being in addition separated by a potting compound, based on an appropriate adhesive compound, intended to form a tight separation comprising a step of circulating, in said external compartment, a polymer solution containing at least one cationic polymer or a mixture of polymers of which at least one polymer is cationic and is a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.  
     
     
         31 . Process according to the preceding claim comprising a step of circulating in said internal compartment simultaneously or not with the circulation in the external compartment, a polymer solution containing at least one cationic polymer or a mixture of polymers of which at least one polymer is cationic and is a hydrophilic polymer selected from the group comprising a polyamine, a diethylaminoethyldextran and a polymer and copolymer containing one or several quaternary ammonium groups.  
     
     
         32 . Process according to  claim 30  or  31  comprising a step of circulating said polymer solution from one end to the other of one or two compartments and then inverting the circulation direction inside the same compartment.  
     
     
         33 . Process according to  claim 30  or  31  comprising a step of circulating said polymer solution from one end to the other of one or two compartments in only one circulation direction.  
     
     
         34 . Process according to  claim 30  or  31  comprising a step of heparinizing the semipermeable membrane consisting, before use, in pre-heparinizing said membrane or, after mounting, in heparinizing said membrane during the rinsing of said device.  
     
     
         35 . Process according to  claim 30  or  31 , comprising a gamma-ray sterilization step after manufacture of said device.